1. Field of the Invention
The present invention relates to a radiation detection device, a radiation image acquiring system, and a method for detecting radiation.
2. Related Background Art
Conventionally, it has been common to allow X-rays to transmit through a subject being a specimen such as food or drugs and make an inspection based on a transmission X-ray image thereof to determine the existence of a foreign substance in a subject. For such an inspection, an X-ray detection device including an X-ray source for irradiating X-rays to the subject and a linear line sensor for detecting a transmission image of X-rays irradiated to the subject from the X-ray source has been used.
However, in the case of detection by a single line sensor with no energy discrimination function, because of the absence of an energy discrimination function, the detection accuracy may decline due to a difference in the composition of a foreign substance contained in the subject (for example, a difference of whether being bone or meat or whether being cartilage or a foreign substance in a meat inspection) and a difference in thickness. Therefore, it has been proposed to arrange in parallel two line sensors for detecting X-rays of different energy ranges, acquire a subtraction image being a difference data image from X-ray images detected by these two line sensors, and thereby improve the detection accuracy irrespective of the composition and thickness of a foreign substance contained in a subject (refer to, for example, Japanese Published Unexamined Patent Application H10-318943).